1. Field of the Invention
The present invention relates to a recording tape cartridge including a case for accommodating therein a single piece of a reel wound by a recording tape such as a magnetic tape that is mainly used as a recording reproduction medium in a computer or the like.
2. Description of the Related Art
Conventionally, a recording tape cartridge has been already known in which a recording tape such as a magnetic tape that is used as a data recording reproduction medium in a computer or the like is wound around a reel, and a single piece of the reel is accommodated in a case that is formed by an upper case and a lower case. To the leading end of the recording tape is secured a leader member that is pulled out by a pullout member of a driving apparatus. An example of the leader member includes a leader pin. The leader pin is formed in a substantially dumbbell shape, has flange portions at both ends of a main body portion of the leader pin, to which the recording tape is secured directly or through a leader tape.
The flange portions of the leader pin are accommodated into concaved holding portions that are formed at an upper case and a lower case near an opening of the case. The leader pin is held, with the height direction of the case being as an axial direction, by the flange portions being pressed by springs or the like. Therefore, when an impact due to a fall or the like is applied to the vicinity of the opening of the case, and the upper case and the lower case are flexed and deformed, separating away from each other (conducting a so-called “deformation of the opening of the case”), it is feared that the flange portions are off-positioned from the holding portions, and the leader pin is inclined and/or removed from the holding portions.
When such a phenomenon occurs, the pullout member of the driving apparatus may unsuccessfully chuck with the leader pin, resulting in a system error. Accordingly, a recording tape cartridge has conventionally been proposed in which the removal of the flange portions from the holding portions can be prevented by forming at the holding portions under-cut grooves with which the flange portions of the leader pin are engaged, i.e., concaved grooves into which the flange portions are entered (see Japanese Patent Application Laid-Open (JP-A) No. 2001-148179, for example).
However, in such a recording tape cartridge, an urging member such as a spring, which presses the flange portions of the leader pin, is provided, thus there is a problem of increasing cost of manufacturing and assembling of the urging member. Further, a recording tape cartridge is proposed in which an outer surface of the flange portion is urged by an urging member such as a spring to press the leader pin in an axial direction (see Japanese Patent Application Laid-Open (JP-A) No. 11-250619, for example). The same problem applies in this case. Further, with such a structure, the aforementioned deformation of the opening of the case cannot be prevented at the time when an impact is applied to the vicinity of the opening due to a fall or the like thereby causing a problem that the flange portions of the leader pin may be off-positioned from the holding portions.
A recording tape cartridge has conventionally been proposed that engaging portions having spring characteristics are formed integrally with an upper case and a lower case, and by pressing with the engaging portions, a leader block is pressed in a height direction of the case (see Japanese Patent Application Laid-Open (JP-A) No. 2003-242741). However, in the leader block, it is difficult to apply a structure that undercut grooves (concaved grooves) are formed and pressing is performed. Accordingly, also in the case of this recording tape cartridge, when an impact is applied to the vicinity of the opening due to a fall or the like, the aforementioned deformation of the opening of the case cannot be prevented, and a problem is caused that the leader block may be off-positioned from the holding portion.